Go generics example

main.go

package main

import "fmt"

type Base interface {
	getID() int64
}

type Person struct {
	ID   int64
	Name string
	Age  uint
}

func (p Person) getID() int64 {
	return p.ID
}

type Vehicle struct {
	ID   int64
	Name string
}

func (v Vehicle) getID() int64 {
	return v.ID
}

func idList[K Base](xs []K) []int64 {
	ids := make([]int64, len(xs))
	for i, x := range xs {
		ids[i] = x.getID()
	}
	return ids
}

func main() {
	ps := make([]Person, 2)
	ps[0] = Person{100, "piyo", 10}
	ps[1] = Person{101, "huga", 30}

	vs := make([]Vehicle, 2)
	vs[0] = Vehicle{1, "ssss"}
	vs[1] = Vehicle{2, "iiii"}

	pids := idList(ps)
	fmt.Println(pids)

	vids := idList(vs)
	fmt.Println(vids)
}